The original box/case was an aluminium box and the buttons/switches were drilled in and there.

The new box is a plastic one and a completely different shape.

Alas now it is a bit too late to think "I should have done it differently".

The original box (top view) was nearly square. The new one is more rectangular and it is oriented that I look at the narrower side/end.

The "front" is only just wide enough that the display fits left - right.Also the Arduino and shield take up 90% of the height.

So there is scaresley any space on the front to put the switches/buttons. Alas the 7 buttons of the shield would be handy, though only one is an absolute must - as I need to press something to turn off the alarm.

On top of that, I need some swithces to control the "mode" of what happens at the alarm time/s.

So I am kind of stuck to "how/where" I am going to put the switches, and what "kind".

Membrane type would be nice as they are low profile and don't need that many holes to be made. They simply stick on.

If I were you, I would eliminate the buttons completely (because of the space limitations). I would remotely control the device through either infrared or bluetooth. You very probably already have a TV (or Apple TV) remote control already, and maybe even an Android phone with bluetooth.Both IR and BT solutions cost about the same as the keypad solution you have in mind. Also, libraries for both are readily available.